This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. This project examines the role that everyday life stresses play in leading to infertility in women and nonhuman primates. It builds on our previous findings that some individuals are very sensitive to stress and readily show stress-induced suppression of reproductive function, while others are stress-resilient and maintain normal menstrual cycles when stressed. We have found that stress-sensitive individuals show lower activity of central serotonergic neurons compared to more stress-resilient individuals as shown both physiologically and by changes in gene expression. In this grant, Specific Aim 1 is to determine if treatment with a selective serotonin reuptake inhibitor (SSRI) will increase the stress resilience of stress-sensitive individuals. Specific Aim 2 is to identify differences in gene expression and activity of central neural systems in stress-sensitive and stress-resilient individuals. Specific Aim 3 examines activity of the hypothalamic-pituitary-adrenal (HPA) axis in stress-sensitive vs. stress-resilient animals.